the atmosphere and environment Flashcards
what percentage of air is oxygen and what is its liquefying temperature?
21%, -183 degree celsius
what percentage of air is nitrogen and what it is its liguefying temperature?
78%, -196 degree celsius
what percentage of air is carbon dioxide and what is its freezing point?
0.03%, -79 degree celsius
what is oxygen used for?
supports combustion, supports all living things
what is nitrogen used for?
used in the manufacture of ammonia, used by plants to produce plant proteins which are consumed by animals, used as a refigerant
where does carbon monoxide come from?
incomplete combustion of carbon-containing fuels in motor vehicles and industries
what harmful effects does carbon monoxide cause?
combines irreversibly with haemoglobin in blood to form carboxyhaemoglobin which prevents the transport of oxygen to body cells
what makes carbon monoxide so dangerous?
it is colourless and odurless
how do you prevent inhalation of carbon monoxide?
use catalytic converters fitted to motor vehicles to oxidise CO into harmless CO2
how is sulfur dioxide formed?
combustion of fossil fuels which contain sulfur impurities in power stations and factories or in volcanic eruptions
what can sulfur dioxide do to humans?
irritates eyes, lungs and breathing passages
what can sulfur dioxide do to the environment?
it can react with oxygen and dissolves in rainwater to form acid rain which corrodes limestone buildings and destroys aquatic life
how can sulfur dioxide be prevented from being released into the atmosphere?
through desulfurisation where SO2 from waste or flue gases produced by coal or oil burning power station
what are the three equations that show how desulfurisaton is conducted?
- CaCO3 (s) + SO2 (g) -> CaSO3 (s)
+ CO2 (g) - CaO (s) + SO2 (g) -> CaSO3 (s)
- CaSO3 (s) + 2 H2o (L) + 1/2 O2 (G) -> CaSO4. 2H2O
how are oxides of nitrogen produced?
nitrogen and oxygen in the air combined at high temperatures inside vehicle combustion engines as well as power plants and factories or in lightning
what does NO2 do to humans?
when inhaled, it irritates the eyes, lungs and breathing passages
what does NO2 do to the environment?
oxides of nitrogen reacts with oxygen and dissolves in rainwater to form acid rain, which corrodes l;limestone buildings and destroys aquatic life and plants + formation of photochemical smog
how can oxides of nitrogen be reduced?
catalytic converters fitted to motor vehicles to reduce NO into harmless nitrogen
how is ozone produced?
chemical reactions between oxides of nitrogen and unburnt hydrocarbons in the presence of sunlight or formed form photochemical reaction between oxygen molecules and oxygen atoms in the lower atmosphere layer
what are the harmful effects of ozone on humans?
chest pain, shortness of breath and throat irritation
what are the harmful effects of ozone on the environment?
ozone with other pollutants form the photochemical smog
how are unburnt hydrocarbons/methane produced?
incomplete combustion of carbon-containing fuels in vehicle engines / decomposition of plant and animal matter
what are the harmful effects of unburnt hydrocarbons and methane on the environment?
can form photochemical smog/methane is a greenhouse gas and excessive amounts of it can lead to global warming
how can we prevent the formation of unburnt hydrcarbons/methane?
using a catalytic converter to remove air pollutants in vehicle exhaust gases by converting harmful gases into less harmful gases
